var common = require('../common'); var assert = require('assert'); var path = require('path'); var fs = require('fs'); var tmp = common.tmpDir; var filename = path.resolve(tmp, 'truncate-file.txt'); var data = new Buffer(1024 * 16); data.fill('x'); var stat; // truncateSync fs.writeFileSync(filename, data); stat = fs.statSync(filename); assert.equal(stat.size, 1024 * 16); fs.truncateSync(filename, 1024); stat = fs.statSync(filename); assert.equal(stat.size, 1024); fs.truncateSync(filename); stat = fs.statSync(filename); assert.equal(stat.size, 0); // ftruncateSync fs.writeFileSync(filename, data); var fd = fs.openSync(filename, 'r+'); stat = fs.statSync(filename); assert.equal(stat.size, 1024 * 16); fs.ftruncateSync(fd, 1024); stat = fs.statSync(filename); assert.equal(stat.size, 1024); fs.ftruncateSync(fd); stat = fs.statSync(filename); assert.equal(stat.size, 0); fs.closeSync(fd); // async tests var success = 0; testTruncate(function(er) { if (er) throw er; success++; testFtruncate(function(er) { if (er) throw er; success++; }); }); process.on('exit', function() { assert.equal(success, 2); console.log('ok'); }); function testTruncate(cb) { fs.writeFile(filename, data, function(er) { if (er) return cb(er); fs.stat(filename, function(er, stat) { if (er) return cb(er); assert.equal(stat.size, 1024 * 16); fs.truncate(filename, 1024, function(er) { if (er) return cb(er); fs.stat(filename, function(er, stat) { if (er) return cb(er); assert.equal(stat.size, 1024); fs.truncate(filename, function(er) { if (er) return cb(er); fs.stat(filename, function(er, stat) { if (er) return cb(er); assert.equal(stat.size, 0); cb(); }); }); }); }); }); }); } function testFtruncate(cb) { fs.writeFile(filename, data, function(er) { if (er) return cb(er); fs.stat(filename, function(er, stat) { if (er) return cb(er); assert.equal(stat.size, 1024 * 16); fs.open(filename, 'w', function(er, fd) { if (er) return cb(er); fs.ftruncate(fd, 1024, function(er) { if (er) return cb(er); fs.stat(filename, function(er, stat) { if (er) return cb(er); assert.equal(stat.size, 1024); fs.ftruncate(fd, function(er) { if (er) return cb(er); fs.stat(filename, function(er, stat) { if (er) return cb(er); assert.equal(stat.size, 0); fs.close(fd, cb); }); }); }); }); }); }); }); }